Is there is any treatment for allergic sinusitis?

Meds or Shots. If allergies are casuing repeated episodes of sinusitis... Get the allergies treated with antihistamines or nasal steroids. Immunotherapy (shots) may also be very beneficial in treating allergies which may reduce the number of sinus infections you get.
Allergies. There are many treatments: salt water washes, oral antihistamines, nasal steroids and nasal antihistamines, oral anti leukotrienes, allergy shots, avoidance, etc. See an allergist for testing and treatment.